Re: [gentoo-user] glibc 2.12.1-r1 seems to not be working correctly

[Alan McKinnon]

Apparently, though unproven, at 21:44 on Sunday 22 August 2010, 
covici@××××××××××.com did opine thusly:

> Alan McKinnon <alan.mckinnon@×××××.com> wrote:
> > Apparently, though unproven, at 20:57 on Sunday 22 August 2010,
> >
> > covici@××××××××××.com did opine thusly:
> > > > There is a way to downgrade for the brave.
> > > >
> > > >
> > > >
> > > > quickpkg glibc
> > > > move the 2.11.? version ebuild you want to your local overlay.
> > > > Edit it and find the check that disallows downgrades. Comment it out.
> > > > Mask glibc2.12
> > > > update glibc
> > > >
> > > >
> > > >
> > > > At this point it's probably very wise to rebuild at least system,
> > > > then revdep- rebuild. Note that rebuilding system might fail in
> > > > which case you are really up the creek.
> > > >
> > > >
> > > >
> > > > Feel free to rip to pieces the dev that committed this version. It
> > > > could not  possibly have undergone decent testing
> > >
> > > I have another idea -- what would I have to restore from backup to
> > > completely cancel the entire update process I have done since yesterday
> > > -- and then I could mask off the bad glibc and be back to something at
> > > least somewhat consistent?
> >
> > I too have another idea - look at emerge.log and tell us what you emerged
> > since yesterday. Then restore those packages.
>
> If I tried that -- how would I downgrade glibc in the process -- I am
> sure I could figure out all the packages, but that downgrade scares me
> -- would I do the packages in reverse order, or what?  I also changed my
> gcc before this update, I could certainly reverse that as well.


It all depends on what tools you have available and how many packages were 
upgraded between yesterday and today. If you have tarballs for at least system 
in your packages dir, then just merge the old ones back. If not, then 
downgrade glibc and either emerge -e system or run revdep-rebuild.

gcc is not a major issue, it simply builds runnable code and links to other 
stuff. As long as the ABI didn't change, and it didn't, gcc will not cause any 
relevant problems. The real problem is glibc which provides the C library. 
Almost everything links to that and it's interfaces can and do change. So 
packages built since that upgrade may well break with a downgrade.

But like I said the best approach will depend on what packages are involved 
and you still haven't provided that list. I used to have a crystal ball that 
could gaze into your mind and your disk to find these answer, but ironically 
it too is now broken by the very same glibc upgrade you are dealing with. So 
you must look into this yourself. However, it's not all bad news - at least my 
fee to you will not increase.




-- 
alan dot mckinnon at gmail dot com